A mobile radio terminal, for example a mobile telephone, needs for its normal operation in the mobile radio network a mobile radio card, i.e. a chip card which contains a subscriber identity module (SIM) used for identifying the user in the mobile radio network and is therefore also called a SIM card.
Mobile radio terminals which are to be used simultaneously with two SIM cards need two mutually independent transmitting/receiving devices for mobile radio signals or, respectively, a transmitting/receiving device with a dual construction of the components needed for parallel data paths to be operated independently of one another, in order to provide for a simultaneous, independent operation of the two SIM cards in their respectively associated mobile radio networks.
Mobile radio terminals having only a single transmitting/receiving device for mobile radio signals which are to be used simultaneously with two SIM cards allow only an alternative operation of the SIM cards, i.e. with these, the user of the device has to switch back and forth between the two SIM cards and their respectively associated mobile radio networks as required.
In a mobile radio terminal which is to be used with two SIM cards simultaneously, it would be desirable to provide for a flexible operation with rapid change between the two SIM cards and their respectively associated mobile radio networks with less expenditure than is represented by two mutually independent transmitting/receiving devices for mobile radio signals and two mutually independent data paths for mobile radio signals.